Transport systems equipped with a rack-and-pinion-type propelling mechanism

ABSTRACT

A transport system comprising a track, a machine supported and/or guided therealong, and a mechanism for propelling said machine along said track that includes at least one rack extending longitudinally of the track and at least one pinion carried by said machine and meshing therewith. The rotation plane of said pinion is inclined to the longitudinal vertical centerplane of the machine at an angle such that the line of intersection of said rotation plane and said longitudinal centerplane lies close to the roll axis of the machine.

United States Patent 1191 Bertin Aug. 26, 1975 1 TRANSPORT SYSTEMS EQUIPPED WITH A [56] References Cited RACK-AND-PlNION-TYPE PROPELLING UNITED STATES PATENTS MECHANISM 190,975 5/1877 Muehle 105/29 R [75] Inventor: Jean Henri Berti, 3,581,666 6/1971 Bertm 104/23 FS Neuilly-sur-Seine, France Primary ExaminerM. Henson Wood, Jr. [73] Assignee: Berlin & Cie, 78-P1aisir, France Assistant Examiner w Keen [22] Filed: Sept 11 1974 Attorney, Agent, or Firm-A. W. Breiner [21] Appl. No.: 505,074 57 ABSTRACT Related U.S. Application Data A k h transport system comprising a trac a mac me sup- [62] 33 :2 g March 1973 ported and/or guided therealong, and a mechanism for propelling said machine along said track that includes 30 F A P D t at least one rack extending longitudinally of the track 1 orelgn "on y a a 72 07481 and at least one pinion carried by said machine and 1 A 4 meshing therewith. The rotation plane of said pinion is Sept. 21, 1972 France 72.33 05 inclined to the longitudinal vertical Centerplane of the machine at an angle such that the line of intersection [52] 105/29 104/23 ggfliglfi of said rotation plane and said longitudinal center- I t C B6) 13/08 plane lies close to the roll axis of the machine.

n 58 Field of Search 1. 105/29 R, 148 MS;

104/23 FS, 134, 132, 118, 89, 147 R, 148 R; 74/422, 461, 462

l 63 26 ik 1 Claim, 2 Drawing Figures TRANSPORT SYSTEMS EQUIPPED WITH A RACK-AND-PlNlON-TYPE PROPELLING MECHANISM This is a division of my patent application filed Mar. 1, 1973, Ser, No. 336,950, which became US. Pat. No. 3,854,418 on Dec. 12, 1974.

The present invention relates to transport systems of the kind including a track, a machine supported and/or guided therealong, and a mechanism for propelling said machine along said track, which mechanism includes at least one rack extending parallel to the longitudinal direction of the track and at least one pinion or cogwheel carried by the machine and meshing with the rack.

The invention is more particularly though not exclusively applicable to cases where said machine is a ground effect machine supported and/or guided along the track with the interposition of at least one fluidcushion at a pressure higher than that of the surrounding medium, or of at least one layer of fluid at a pressure below that of the surrounding medium.

A machine travelling along a track is frequently subject to rolling motion, that is to say to rocking from side to side about a so-called roll axis.

In cases where such a machine is propelled by a rackand-pinion mechanism, this phenomenon is aggravated by the fact that the transverse forces associated to such rolling motion are transmitted to the track, at least partially, by the toothed pinion and combine with the pinion/rack interaction force (which force is contained in the rotation plane of the pinion).

Ground effect machines, whose only direct contact with the track is via the rack-and-pinion propelling mechanism, are particularly sensitive to this phenomenon.

Generally speaking, it is an object of the present invention to reduce the magnitude of the rolling motion in a transport system of the aforementioned kind, in order primarily to improve the conditions under which the payload is transported and increase passenger comfort.

In an improved rack-and-pinion-driven transport system according to this invention, the rotation plane of the pinion is therefore inclined relatively to the longitudinal vertical centerplane of the machine at an angle such that the line of intersection of said rotation plane and said longitudinal centerplane lies close to the roll axis of the machine.

With such an arrangement, the leverage which can be exerted about the roll axis by the forces contained in the rotation plane of the pinion is nil or very small, as a result of which the moment tending to rock the machine about that axis is in turn greatly reduced or even nil. The extent of the rolling motion is thus considerably limited.

The description which follows with reference to the accompanying non-limitative exemplary drawings will give a clear understanding of how the invention can be carried into practice.

In the drawings:

FIG. 1 shows in diagrammatic cross-section a transport system comprising a machine propelled along a track by means of at least one rack-and-pinion mechanism according to the invention; and

FIG. 2 is a diagrammatic illustration of an alternative embodiment of the transport system shown in FIG. 1.

Reference is first had to FIG. 1, which shows a transport system comprising a machine 25 capable of travelling along a track 17. In the exemplary embodiment shown in the drawing, this machine is a ground effect machine supported and guided along said track with the interposition of fluid cushions.

In cross-section the track 17 is of inverted T-shape and comprises a bearing portion 1 17 which may be substantially horizontal and a median guiding extension 217 which may be substantially vertical. The fluid cushions are confined by chambers such as plenum chambers 15, 16, which are supplied by means (not shown) with fluid at a pressure greater than the pressure of the surrounding medium.

Alternatively, the machine 25 may be supported and- /or guided through the agency of fluid-layers at a pressure below the pressure of the surrounding medium.

Reference numeral 63 designates the longitudinal vertical centerplane of the machine, and reference numeral 65 its roll axis. As is well-known, the roll axis is a longitudinal instantaneous rotation axis whose location in a given machine depends on the location of the centre of gravity of the machine and on the elasticity and damping characteristics of the suspension system of the machine with respect to the track.

The machine 25 is propelled along the track 17 by a mechanism comprising two rack-and-pinion sets, each of which includes a rack l disposed along the track and a toothed pinion or cogwheel 2 carried by the machine. Each cogwheel 2 is angularly fast with a shaft 9 driven by a motor 26 through reduction gearing 27. The two cogwheels 2-2 are arranged symmetrically in relation to the longitudinal vertical centerplane 63 of the machine, as are the associated racks ll. Preferably, each of these racks is of the elastic type described in my parent application.

As shown in the drawings, the rotation plane 64 of cogwheel 2 is inclined relatively to the longitudinal vertical centerplane 63 of the machine at an angle such that the line of intersection of said rotation plane and said longitudinal centerplane coincides substantially with, or lies very close to, the roll axis 65 of the machine.

This arrangement ensures that the moment, about the roll axis 65, exerted by the forces contained in the rotation plane 64 of the cogwheel is nil or very small, as a result of which the moment tending to rock the machine 25 about said axis is in turn greatly reduced.

The embodiments illustrated in FIGS. 1 and 2 differ only in respect of a detail concerning the manner of securing the rack l to the track 17. In FIG. 1, the rack l is shown fixed to the bearing portion 1 17 of the track, whereas in FIG. 2 it is shown secured to the median guiding extension 217 thereof.

What I claim is:

I. In a transport system comprising a track, a machine supported and/or guided therealong, and a mech' anism for propelling said machine along said track, which mechanism includes at least one rack extending longitudinally of the track and at least one pinion carried by said machine and meshing therewith, the improvement wherein the rotation plane of said pinion is inclined to the longitudinal vertical centerplane of the machine at an angle such that the line of intersection of said rotation plane and said longitudinal centerplane lies close to the roll axis of the machine, 

1. In a transport system comprising a track, a machine supported and/or guided therealong, and a mechanism for propelling said machine along said track, which mechanism includes at least one rack extending longitudinally of the track and at least one pinion carried by said machine and meshing therewith, the improvement wherein the rotation plane of said pinion is inclined to the longitudinal vertical centerplane of the machine at an angle such that the line of intersection of said rotation plane and said longitudinal centerplane lies close to the roll axis of the machine. 